This invention relates to a rapid no-bake binder composition for a foundry aggregate. In a particular aspect, this invention relates to a rapid-cure resin composition for use in preparing cores and molds for foundry operations.
Cores useful in making metal castings are customarily made by placing a foundry aggregate, usually silica sand which has been admixed with a suitable binder, against a shape or pattern and then hardening the binder, as by polymerization. The resulting core is a self-supporting structure which forms a part of a mold assembly.
The cores themselves are made by a variety of processes employing a wide variety of binders. One of the processes in commercial use today is generally known as the rapid no-bake process. In this process, a resinous binder is mixed with a catalyst and sand and placed in a core box or a mold. It cures rapidly at ambient temperatures and can be stripped from the core box or mold in a matter of a few minutes. Binders of this type have been described by M. J. Holik, U.S. Pat. No. 4,116,916; M. J. Holik and J. F. Kraemer, U.S. Pat. No. 4,172,068 and J. Robins, U.S. Pat. Nos. 3,676,392 and 3,726,867.